1. Field of the Invention
The present invention relates to a digital camera and an image reproducing apparatus having a function of reproducing and displaying images recorded in recording media, as well as a related image reproducing method.
2. Description of the Related Art
General digital cameras compress and record a picked up image in a recording medium. A method is known which is operative at this time, to decimate some data from the picked up image to generate a small-sized non-compressed image (also referred to as a xe2x80x9cthumbnail imagexe2x80x9d) and then to record the thumbnail image in a recording medium together with a compressed image (referred to as a xe2x80x9cmain imagexe2x80x9d). Further, with digital cameras comprising a liquid crystal display section (LCD) functioning to allow recorded images to be checked or as an electronic view finder, an image recorded in the recording medium can be reproduced and displayed on the liquid crystal display section. Accordingly, the next or preceding image is sequentially displayed in response to a user""s operation such as sequential frame feeding or reverse frame feeding.
Recent digital cameras use a large amount of data for recorded images due to an increased number of pixels in a CCD. Thus, a longer time is required to record or reproduce images, so that users may feel uncomfortable about operations. To avoid such an uncomfortable feeling, the digital camera disclosed in Japanese Patent Application Publication No. 10-79913 first displays the thumbnail image, which requires a shorter time for reproduction, and then processes the main image, thereby reducing the time to wait for a decompression process on the main image to be completed. Furthermore, the digital camera disclosed in Japanese Patent Application Publication No. 10-63688 has a function of retrieving a reproduced image at a high speed.
The proposed digital camera, however, cannot reduce the processing time required after an instruction for reproduction and display (instruction for the next or preceding image) has been given and before the main image is displayed.
The present invention is provided in view of these circumstances, and it is an object thereof to provide a digital camera and an image reproducing apparatus and method which can reduce a waiting time when a compressed image (main image) recorded in a recording medium is reproduced and displayed on a display device, and which allows the user to promptly check the reproduced image.
To attain this object, the present invention is directed to a digital camera, comprising: an image pickup device which converts an optical image into an electric signal; a recording device which records image data obtained via the image pickup device, in a recording medium; a readout device which reads out image data stored in the recording medium; a storage device which stores the image contents read out by the readout device; a display device which displays the image contents stored in the storage device; an instructing device through which an instruction is inputted to change an image as a display target; and a control device which, before the instruction is given by the instructing device, reads out image data other than the current display target from the recording medium to store the data in the storage device as prepared images for display, and which, when the instruction is given by the instructing device, reads out a prepared image corresponding to the instruction, from the storage device and provides the image to the display device to cause the display device to display the image corresponding to the instruction.
The instructing device gives, for example, an instruction for sequential frame feeding or reverse frame feeding. According to the present invention, before a user inputs the instruction for the sequential or reverse frame feeding using the instructing device, the image data is beforehand read out from the recording medium, decompressed, and held in the storage device inside the digital camera as the prepared images for display. This reduces the time required to access the recording medium and execute the decompression process when the user has inputted the instruction for the frame feeding. According to one aspect, as the prepared image, an image before or after the current display target image is stored in the storage device.
According to another aspect of the present invention, the digital camera is characterized in that an image picked up by the image pickup device is recorded in the recording medium in a form of an image file including data on a main image showing the picked up image and data on a thumbnail image obtained by reducing the main image to a specified size; the digital camera further comprises a display mode switching device which switches between a multi-reproduction and display mode for displaying a plurality of frame images at a time in a predetermined arrangement form and a one-frame reproduction and display mode for displaying one frame image; and when the multi-reproduction and display mode is selected, the data on the thumbnail image is read out from the recording medium as the prepared image and then stored in the storage device.
According to still another aspect of the present invention, the digital camera further comprises a size converting device which adjusts an image size depending on a resolution of the display device; and image data having a size thereof adjusted by the size converting device is stored in the storage device as the prepared image. Furthermore, according to yet another aspect of the present invention, the digital camera further comprises a video output terminal for outputting a video signal to an exterior, and has a function of automatically adjust the image size of the prepared image depending on a resolution of an image display device connected to the video output terminal.
The present invention also directed to an image reproducing apparatus, comprising: a readout device which reads out image stored in a recording medium; a storage device which stores the image contents read out by the readout device; a display device which displays the image contents stored in the storage device; an instructing device through which an instruction is inputted to change an image as a display target; and a control device which, before the instruction is given by the instructing device, reads out image data other than the current display target from the recording medium to store the data in the storage device as prepared images for display, and which, when the instruction is given by the instructing device, reads out a prepared image corresponding to the instruction, from the storage device and providing the image to the display device to cause the display device to display the image corresponding to the instruction.
According to the present invention, there is provided an image reproducing method of reading out image data stored in a recording medium and displaying an image on a display device, the method being characterized by comprising reading out image data other than a current display target to store the data in a storage device for display as prepared images for display, before an instruction to change an image as a display target is inputted, and reading out a prepared image corresponding to the instruction, from the storage device and providing the image to the display device to cause the display device to display the image corresponding to the instruction, when the instruction to change the image is inputted.